I have implemented some connection classes, using Boost ASIO, to replace some low level C code in an application, and everything is working great, except for one problem. Basically, I have a UdpConnection class that does synchronous read and write, but it uses async methods to handle time-outs as per the boost examples. The problem is I can't figure out how to make it threadsafe. I have tried adding strands to the event handlers to make this class threadsafe (code below), but that isn't working. I suspect it is because of the way timeout is implemented. I have included my code in 4 classes in pastebin. Single threaded is working fine. I also have TcpConnection and UnixSocketConnection classes that don't need to be shared amongst multiple threads and they work fine. However, I can't get multi-threaded UDP code to work. Am I missing something? Sources below: * Connection.h && AsioConnection.h http://pastebin.com/Cbbw37gL * UdpConnection.h && UdpConnection.cpp http://pastebin.com/VLnHBnPs